Posted in reply to the post by rossmen:
At the time the case went to the supreme court I remember the justification for the denial of the applicant was that it's a boring job and we want people who will follow the rules. The justices agreed. I don't know if this criteria is still used, probably depends on the department. I know smart cops too. The job has evolved, some places. Round here they are expected to be front line social workers who carry a gun and are licensed to kill. It takes multiple types of high intelligence to do this successfully.